The patent language would worry me a lot. It would be tough to have to admit, up front, "even if this widget becomes popular I can never build a business on it."

But I'm not using Arduino, so idk.

The cool thing about an Arduino is you can just buy the boards and use them in a commercial product. This isn't something you can do with other boards. Some people have said the license requires you to disclose your firmware, but that's not the way I read it and I've never heard of anyone being compelled to release anything (unless they modify any GPL covered code).

Not all platforms give you the right to do this. For example, if you buy a dev board from STM - it's only licensed for research and development. Also, because you might want to continue to sell the same thing for years, and the board designs were open-sourced, you could buy the same part for years and years. So you can continue to sell your CNC kit that uses an Mega 2560 without worrying about Arduino coming after you or that they'd discontinue that part.

> "even if this widget becomes popular I can never build a business on it.

With the exception of a handful of applications for their higher-end boards, I would think most of this flotilla of ships has already sailed, just on a cost basis?

Especially lately. So much more choice.